The present invention relates to a tuning device for a television or radio receiver.
FIGS. 1 and 2 depict a conventional tuning device for a television receiver. The tuning device has a dial drum 1 rotatably mounted in a frame 2 by a shaft 3. The dial drum 1 has an internal toothing 4a with which a drive pinion 4 is engaged. The drive pinion 4 is rotatably mounted in a frame 2a by a shaft 5 having a knob 6. The shaft 3 of the drum 1 is operatively connected in sliding contact with a rheostat 7 provided on the outside of the frame 2. Thus, rotation of the knob 6 causes the dial drum 1 to rotate through the drive pinion 4.
In such a device, the diameter of the drive pinion 4 cannot be reduced below a limit value. Accordingly, in order to increase the gear reduction ratio for fine tuning, the diameter of the display drum must be increased, which in turn causes an increase in the size of the tuning device. Furthermore, the shaft 5 of the knob 6 is eccentric with reference to the center of the dial drum 1. This construction gives the user the impression that the knob and dial drum form a disconnected structure.